The people who planned and executed the 9/11 attack are still operating in the area and plotting attack against the United States, the White House on Tuesday said, adding this is the reason why America continues to be in Afghanistan.

"We should keep in mind that the reason we are in Afghanistan is because the people who plotted and executed the attacks on 9/11 are still operating there and are plotting attacks against Americans even now," White House Deputy Press Secretary Bill Burton told reporters abroad Air Force One traveling with US President Barack Obama, en route to Andrews Air Force Base from Mexico.